Sweep conveyor assembly for use in a silo or granary
A sweep conveyor assembly is provided for use in a silo or granary (70) having a floor (71), a generally cylindrical wall (72) upstanding from the floor (71) and a discharge apparatus (1) for discharging material (74) from a centre of the floor (71) to an exterior location. The sweep conveyor assembly has a sweep conveyor (S) for transporting material (74) inside the silo (S) or granary towards the centre of the floor (71) where it can be discharged by the discharge apparatus (1), a holder (H), and a link mechanism (8) for connecting the sweep conveyor (S) to the holder (H), and in turn having a connection link (L) with a first end (83) and a second end (84). The first end (83) is connected to the holder (H) at a fixed pivot point and the sweep conveyor (S) is connected to the second end (84) of the connection link (L) at a movable pivot point. The connection link (L) rotates about the fixed pivot point, forming a first angle (α) between the connection link (L) and the holder (H), and the sweep conveyor (S) rotates about the movable pivot point, forming a second angle (β) between the sweep conveyor (S) and the connection link (L). The link mechanism (8) controls a ratio between the first angle (α) and the second angle (β), with a magnitude of the first angle (α) and second angle (β) controlled by an angular position of the sweep conveyor (S).
The present invention relates to a sweep conveyor or sweep auger, assembly for use in a silo or granary, having a floor, and a generally cylindrical wall, upstanding from the floor and a discharge apparatus, for discharging material, from a centre of the floor to an exterior location, the sweep conveyor, assembly comprising:
-
- a sweep conveyor, for transport of material, inside the silo or granary, towards the centre of the floor, where it can be discharged by the discharge apparatus,
- a holder,
- a link mechanism for connecting the sweep conveyor to the holder, said link mechanism comprising a connection link having a first end and a second end.
The invention relates to a silo, for storage of bulk material, for example grain, where the unloading of the silo is made with a diagonally standing discharge apparatus, for example a screw conveyor, standing diagonally from the bottom centre of the silo, out through the silo wall higher up, in combination with a sweep auger or sweep conveyor, that brings material, in to the center. The fact that the diagonal evacuation screw conveyor consists an obstacle in the silo for the movement of the sweep conveyor, results in that the sweep conveyor cannot reach a whole tour around the inside of the silo, and thus a lot of material remains that has to be removed manually. This invention proposes a main solution to this.
A flat-bottom silo, for grain and other bulk material, is unloaded in two steps:
The major part of the volume is emptied via gravity transport down to a cone in the centre of the silo floor. From the bottom of the cone, the material is evacuated from the silo by a screw or other kind of conveyor. When the silo is evacuated in this way, the evacuation will eventually cease as all the material above the angle of rest from the centre cone is evacuated and no more material can fall down via gravity to the cone.
When the evacuation has stopped due to the above, usually a sweep conveyor, or a sweep auger is used to move the material on the floor in to the central bottom cone. This sweep conveyor is placed radially, with a fixed rotation point in the centre of the silo, and the other end walking around the inside of the silo wall, driven by a wheel, to successively move segment by segment of the material into the centre and the bottom cone.
A number of problems are associated with the unloading of the silo.
Devices for evacuation of the silos, that are built under the silo floor of the flat bottom silos leave a free space on top of the floor for the sweep conveyor, S, to rotate a complete round, and thus evacuate the remaining quantity of the stored material. This solution is expensive for certain kinds of use, for example when storing grain on farms. In order to reduce the investment, often a screw conveyor, standing diagonally at the bottom of the cone, is used instead, leading the material out through the silo wall. This allows to put the grain directly onto the bed of a truck for further transport. However, this fixed mounted, diagonally standing, screw conveyor is in the way for the movement of the sweep conveyor, and does not allow the sweep conveyor, to turn a complete 360 degrees round around the inside of the silo. Up to approx. ¼ of the material, left on the floor after step 1 above, can still be left after the sweep conveyor has completed its maximum portion of its circle. The remaining material has to be removed manually, which is very labour demanding as this can be 10-15 metric tons or more in large silos.
An attempt to solve the problem above is to use a pivoting mounting point, 11, of the sweep conveyor, S, as described by U.S. Pat. No. 4,669,941 and Canadian Patent No. 1 210 920.
Another problem is that the sweep conveyor, when placed on the floor of the silo, is still covered with material, when the central diagonal screw conveyor has emptied all the material that it can bring out by itself. Many types of sweep conveyors cannot start when they are covered with material. This can be handled in two possible ways: Either the sweep conveyor is uncovered by manually removing the material, or, a type of sweep auger or conveyor is used that is portable, that is not entered into the silo until it is the moment to start using it, after the maximum quantity of material has been removed with only the gravity transport, as described above. Both ways are very laborious and can be risky from a labour safety point of view.
There is therefore clearly a need for an improved sweep conveyor, S, assembly that overcomes the problems above.
SUMMARY OF THE INVENTIONThe object of the present invention is to eliminate or at least to minimize the problems mentioned above. This is achieved through a sweep conveyor assembly according to the description herein.
According to the invention, the link mechanism is arranged to control a relation between the first angle and the second angle, and a magnitude of the first angle and second angle is controlled by an angular position of the sweep conveyor. Due to the configuration of the connection link and link mechanism, and the ability to control the first and second angle, the operation of the sweep conveyor is considerably improved, facilitating the removal of material from the silo and the efficiency of the process of emptying the silo.
According to an aspect of the invention, the first angle is a function of the second angle. Both these angles are directly determined as a function of the progress of the sweep conveyor along the inside of the silo wall. Thereby, the movement of the sweep conveyor is further improved and the risk of problems during operations minimized. Preferably, the first angle is equal to the second angle.
According to another aspect of the invention, the holder is mounted on the floor of the silo or granary, or on the discharge apparatus. Thereby, the sweep conveyor is held securely and the presence of additional structures inside the silo can be avoided.
According to a further aspect of the invention, the connection link and the link mechanism are permanently connected to the holder, and/or the sweep conveyor is detachably mounted on the link mechanism. Thereby, the link mechanism is held stably whereas the sweep conveyor can be removed, facilitating repairs and maintenance.
According to another aspect of the invention, the link mechanism comprises an additional second link, attached at its first end through a joint at a fixed pivot point at a position on the holder different from the fixed pivot point of the connection link, and having its second end attached to the sweep conveyor through a joint at a movable pivot point, at another position compared to the one where the connection link is attached to the sweep conveyor. Thereby, the control of the first and second angles can be achieved in a convenient and reliable way, and the link mechanism and its movements are rendered sturdy and reliable.
According to another aspect of the invention, the link mechanism comprises at least two wheels arranged in rolling interaction with each other, wherein the connection link is formed/located between a center of rotation of two of the wheels, and wherein the wheels are preferably cog wheels. Thereby, the control of the first and second angles can be achieved in a convenient and reliable way, and the link mechanism and its movements are rendered sturdy and reliable.
According to another aspect of the invention, the link mechanism comprises two wheels which are not touching each other, wherein the connection link is formed between a center of rotation of two of the wheels, and where the wheels are connected by a wire or chain or belt. Thereby, the control of the first and second angles can be achieved in a convenient and reliable way, and the link mechanism and its movements are rendered sturdy and reliable.
According to a further aspect of the invention, the link mechanism comprises a hydraulic or pneumatic or electric actuator between the first end and the second end, wherein the connection link is located between the joints at the fixed pivot point and the movable pivot point. Thereby, another sturdy and convenient of realizing the invention is achieved, giving an excellent control over the first and second angles.
According to another aspect of the invention, the sweep conveyor is connected to the connection link via a vertical connection or adapter, in such a way that the sweep conveyor is beneath the connection link during operation. Thereby, the centre of the silo at floor level can be kept clear of the connection link, link mechanism and holder and thereby facilitate the flow of and removal of material from the silo. Furthermore, the risk of damages to the link mechanism and the driving gear from the motor drive of the sweep conveyor, and other components, due to interference with the material in the silo, can be kept low.
According to a further aspect of the invention, the connection link comprises a joint in the middle so that the second end of the connection link can pivot in relation to the first end of the connection link, forming a third angle between said second and first ends of the connection link. Thereby, material directly beneath the fixed pivot point conveyor can also be reached and removed by the sweep conveyor.
According to another aspect of the invention, the connection link comprises a joint in the middle so that the second end of the connection link can pivot in relation to the first end of the connection link, forming a third angle between said second and first ends of the connection link, and where the sweep conveyor comprises a first and a second conveyor portion that are connected to each other by a sweep conveyor joint, the first conveyor portion being configured to be connected to, and thus following the same movements, as the second end of the connection link that is pivotable in relation to the first end of the connection link. Thereby, the removal of material can be made even more efficient and the flow down into the bottom cone is improved.
According to a further aspect of the invention, the sweep conveyor is essentially horizontal when mounted on the link mechanism, but one end portion of the sweep conveyor extends upwards at a fourth angle from the horizontal direction, said end portion being at the end configured to be connected to the link mechanism. Thereby, removal of material at the centre of the silo can be facilitated in cases when the bottom cone has a small diameter, or in case there is no bottom cone.
According to another aspect of the invention, the sweep conveyor is arranged to allow pivoting upwards about a movable pivot point and to be attached to a conveyor holder provided on or beside the discharge apparatus or standing on supports on the floor or being attached to the silo wall, or a combination of these. Thereby, the start of the operation of the sweep conveyor is facilitated and the risk of damages due to pressure from material on top of the sweep conveyor eliminated.
Many other benefits and advantages of the invention will become readily apparent to the person skilled in the art in view of the detailed description below.
The invention will now be described in more detail with reference to the appended drawings, wherein
As used herein, the term sweep conveyor includes all kinds of devices suitable for moving material on a granary floor towards a centre of a silo, such as sweep augers and the like.
The problems underlying the invention will now be described in more detail with reference to
After the major part of the volume is emptied via the cone 2 in the centre of the silo floor 71, as described above, the diagonal evacuation screw conveyor 1 has removed all the material 74 that is possible with only gravity bringing the material 74 to fall down into the centre cone 2, without any additional tools. Material 74 that is located below the specific angle of rest δ of the material 74 is not transported by gravity and is therefore still left immobile in the silo 70. At this stage, illustrated by
The solutions to these problems according to the present invention will now be described with reference to these same figures.
A horizontal connection link L (minimum length is half of the sum of the widths of the sweep conveyor and the evacuation screw conveyor) is mounted at its first end 83 mounted through a first joint 10 with a vertical rotation axis, fixed to a holder H close to the centre of the silo, for example it can be mounted above the lower end of the diagonal evacuation screw conveyor 1. See in
These two angles are continuously mutually dependent thanks to a link mechanism 8. The link mechanism 8 comprises the connection link and a device to control a ratio or relation between the first angle α and the second angle β. The magnitude of these two angles are both determined by the advancing of the sweep conveyor, S, i.e. an angular position of the sweep conveyor S. The change of the angles is driven by the motion of the sweep conveyor, S. ρ is the angle of progression of the sweep conveyor. The circular pathway of the second joint 11 at the movable pivot point of the sweep conveyor S, is shown with a dotted arrow γ, illustrating how the second joint 11 at the movable pivot point of the sweep conveyor S is moved sideways to increase the reach of the sweep conveyor S. In this way, γ also illustrates the change of the first angle α of the connection link L as it moves sideways. For simplification, the central cone 2, in the floor 71, is not shown, but it is below the space over which the link L is turning. Two alternative examples of movements of the connection link L and the sweep conveyor S are shown in
Thus, the link mechanism 8 controls the pivoting of the link L in relation to the holder H and the angle between the link L and an axis along a geometrical centre of the holder H as shown in
The link mechanisms 8 to control the first and second angles α, β are of the following types, described herein as embodiments of the present invention
-
- A: With a an additional, second link, 20
- B: With wheels, for example cogwheels, 31, 32, 33, 34, 35, 36
- C: Hydraulic, pneumatic or electric actuators, 41 and 42
- D: With a chain, a belt or a wire, 39
Each one of these four types can be designed to let the connection link L turn either from or towards the diagonal evacuation screw conveyor 1 (see
The mechanisms are generally mounted on a holder H, preferably in the form of a frame, above the lower end of the diagonal evacuation screw conveyor 1.
Additional variations on the embodiments described above are:
E: A solution according to A-D with rotating movements simultaneously in three different joints, 10, 11 and 12. The first, second and third angles α, β and ε of the first 10, second 11 and third 12 joints do not necessarily have to be the same. This solution allows the sweep conveyor 1 to turn more than 360 degrees and thus bring also the material 74 that is straight under the diagonal evacuation screw conveyor 1.
F: A solution according to E, but where also the sweep conveyor S itself can bend in the second joint 11, in order to allow the material 74 to arrive as close to the bottom cone 2 as possible, which is an advantage if the cone 2 has a small diameter not allowing enough good evacuation for the solution E.
G: A solution according to any one of the solutions A-F, but where the sweep conveyor S is also bent upwards in a seventh vertical joint 53 close to the centre of the silo 70, in order to improve the evacuation of material 74, in case the bottom cone 2 is shallow or in case there is no bottom cone.
H: A complement to all the above solutions is that a peripheral end 82 of the sweep conveyor S is lifted up and being fixed by a vertical support, 60 and 61, before the silo 70 is being filled with material 74 so that the sweep conveyor S shall not be covered with material 74 but instead it shall be free above the sloping surface 75 of the angle of rest δ of remaining material 74, when the diagonal evacuation screw conveyor 1 has evacuated as much as possible without the use of the sweep conveyor S. This allows to avoid the following two labour intensive alternatives: 1. A portable sweep conveyor S that is carried into and mounted inside the silo 70 at the moment when it is needed, and that has to be carried out again before the silo 70 will be filled again, and 2. A fixed installed sweep conveyor S that gets covered with material 74 on the floor 71, and therefore has to be uncovered manually with a shovel before it can be used.
The proposed solutions to the link mechanism 8 for the embodiments of the present invention are preferably mounted on a holder H (or frame or gantry), preferably placed on the floor 71 standing over the lower, central end of the diagonal evacuation screw conveyor 1 near the centre of the silo 76 and the bottom cone 2, see
The sweep conveyor S is hanging below the link mechanism 8, so that its installation is not in the way for the movement of the material 74, running from above and into the bottom cone 2 below the sweep conveyor S (which it risks to do if the connection link L is placed under the sweep conveyor S), and so that it does not limit the movement of the sweep conveyor S (which it risks to do if the connection link L is located beside the central end 81 of the sweep conveyor S).
The installation can easily be adapted to the individual geometry of the silo 70, by allowing
-
- an adjustable distance between the peripheral end 82 of the sweep conveyor S and the silo wall 72
- an adjustable first joint 10 being the fixed pivot point of the connection link L, so that the distance between the central end 81 of the sweep conveyor S and the lower part of the diagonal evacuation screw conveyor 1 can be adjusted
- an adjustable height of the central end 81 of the sweep conveyor S above the bottom cone 2
See some examples of these adaptable installations in
The adapter A to connect the sweep conveyor S to the connection link L can be adapted with different designs to fit different types of sweep conveyors, and this statement applies to any one of the solutions of this invention. There is no limit in the possible designs of the adapter A, as long as it connects the second end 84 of the connection link L through the second joint 11 to the sweep conveyor S, and allows the sweep conveyor S to pivot around this second joint 11 as a movable pivot point. The adapter A comprises a sixth vertically turnable joint 6, so that the peripheral end 82 of the sweep conveyor S can be lifted up, while the central end 81 is still at the same height as the sixth joint 6. The idea is that the peripheral end 82 can be lifted at least to a height allowing it to run freely above the angle of rest δ of the surface 75 of the material 74, being left in the silo 70, when it is the moment to set the sweep conveyor S into operation (See
Examples of these aspects of the installation of the sweep conveyor S and its connection to the holder H will be given in some of the detailed descriptions of the solutions later on in this text, however the same principles will be applicable for all the solutions.
The especially advantageous embodiments A-H will now be described in more detail with reference to the drawings.
A. Solutions with an Additional, Second Link 20 to Control First and Second Angles α and β at the First and the Second Joints 10 and 11 of the Connection Link L
An additional second link 20 is connected with a fourth joint 21 and a fifth joint 22 at each one of its two ends, the fourth joint 21 being connected to a fixed pivot point, preferably connected to the holder H, and the fifth joint 22 being connected to the the sweep conveyor S. As the sweep conveyor S moves around along the inner walls 72 of the silo 70, the additional, second link 20, in this embodiment preferably a pivot arm, forces the sweep conveyor to push the connection link L to turn, in a way that the second joint 11 at the movable pivot point of the sweep conveyor S will move sideways and allow the sweep conveyor S to make a complete 360 degrees turn around the silo 70 without being hindered by the diagonal evacuation screw conveyor 1. The solution A1 describes the straight circular movement, see
B. Solutions Using Wheels to Control the First and Second Angles α and β at the First and Second Joints 10 and 11 of the Connection Link L
A wheel 32 is placed with its axis aligned with the second joint 11 at the movable pivot point of the sweep conveyor S. This wheel is called the second wheel 32 and it follows the same movement as the sweep conveyor S because it has its axis in the second joint 11 through which it is fixed to the adapter A and thus it is fixed to the sweep conveyor S. As the traction wheel 5 at the peripheral end 82 of the sweep conveyor S forces the sweep conveyor S to advance along the inner wall 72 of the silo 70, the second wheel will thus follow the same movement. Due to the location of the second wheel 32 at the second joint 11 at the second end 84 of the connection link, the connection link L will force the second wheel 32 either to be in contact with a first wheel 31 that is fixed to the holder H, having its center aligned with the axis of the first joint 10 connecting the connection link L to the holder H, see
The solution B1 describes the straight circular movement, see the
It can be noted that with the described solutions, it is an advantage to have a protection like a plate or small hood above the wheel mechanisms so that the wheels can rotate freely without getting anything of the material 74 stored in the silo 70 to get stuck around and between the wheels.
In order to allow smaller wheels than in
C. Solutions Using Hydraulic, Pneumatic or Electric Actuators to Control the First and Second Angles α and β at the First and Second Joints 10 and 11 of the Connection Link L
Instead of cogwheels, as in the solutions under B above, double acting hydraulic or pneumatic actuators, active in both directions, each one with two connections for hoses (one to turn right and one to turn left), can be used to control the first and second angles α and β in
As an additional variant of the solution C, the hydraulic or pneumatic actuators can be replaced by electric actuators that can be steered with any kind of control strategy, but preferably a signal that steers the actuators so that the first and second angles α and β are the same. This can best be achieved with only one electric actuator placed at one of the first and second joints 10 or 11, as the angle of the other joint will automatically be controlled by the movement of the sweep conveyor S driven by its peripheral traction wheel 5. If the actuator is mounted to control the first angle α in the first joint 10, then it would preferably be steered by an angle sensor for the second angle β in the second joint 11. If the actuator is mounted to control the second angle β in the second joint 11, then it would preferably be steered by an angle sensor for the first angle α in the first joint 10. For both cases, the preferable control strategy is to let the two angles be equal.
D. Solutions Using a Chain, a Wire or a Belt, to Control the First and Second Angles α and β at the First and Second Joints 10 and 11 of the Connection Link L
The movements illustrated for solutions B1 and B2 can also be achieved by the use of a chain, a belt or a wire 39 between the first and second wheels 31 and 32. See
E: A Solution with a Divided Link Turning in Two Steps
This is an extension of the solutions B, C, and D, which can allow the sweep conveyor S to turn more than a complete tour of 360 degrees, and thus it can remove also the material 74 that otherwise can potentially be left below the diagonal evacuation screw conveyor 1. In principle it comprises using a third joint or link pivot 12 that divides the connection link L into a first, central part 13, connected at one end through the first joint 10 to the holder H at the fixed pivot point of the connection link L, and a second, peripheral part 14 that is connected to the sweep conveyor S at the second joint 11 at the movable pivot point of the sweep conveyor, these both parts being mutually connected in an additional third joint 12. Alternatively, a third, central link 13 and a fourth, peripheral link 14 connected to each other with one additional third joint 12 can be used: The third link 13 connected at its first end to the holder H at the first joint 10 at the fixed pivot point and to its second end through the third joint 12 to the fourth link 14, and this fourth link 14 is connected at its first end through the third joint 12 to the second end of the third link 13 and at its second end through the second joint 11 to the sweep conveyor S at the movable pivot point of the sweep conveyor S. Between the third link 13 and the fourth link 14, or analogously, between the first and the second parts 13 and 14 of the link, a third angle c is formed, so that the angle of progression of the sweep conveyor ρ relative to a horizontal projection of the diagonal evacuation screw conveyor 1 is the sum of the angles α β and ε. The length of the fourth link 14 does not have to be the same as the length of the third link 13, to give flexibility to adapt to various setups of the silo 70. The first, second and third joints 10 11 and 12, can be mutually controlled through any one of the mechanisms in the three solutions B, C, and D, however preferably by the straight circular movement. The third link 13 allows the sweep conveyor S to turn a complete turn around the silo, from a starting point of the third link 13, parallell to the diagonal evacuation screw conveyor 1, to an end point also parallell to the diagonal evacuation screw conveyor 1, but on its other side. The fourth link 14 allows some extra rotation so that the sweep conveyor S reaches behind and below the diagonal evacuation screw conveyor 1. This means that the control of the first, second and third angles α β and ε in the first, second and third joints 10 11 and 12 is achieved in two steps simultaneously, see the angles shown with dotted arrows in
Note that the example solution in
F: A Solution with a Divided Link Turning in Two Steps, where the Central First Portion 51 of the Sweep Conveyor S is Following the Movement of the Fourth Link 14, with a Universal Joint Dividing the Sweep Conveyor S
This solution allows that the material 74 is brought closer to the central cone 2 in the silo floor 71, which is an advantage if the cone 2 has a small diameter that makes it difficult to bring the material 74 straight into the cone 2 with the solution E, as the sweep conveyor S risks to be too much to the side of the cone 2. Then a sweep conveyor S can be used that is divided in a central first portion 51 and a peripheral second 52 portion, where the two parts are connected in a seventh joint 53. The central first portion 51 follows the movement of the fourth link 14 and thus it has the same angle as the fourth link 14. The movement of the peripheral second portion 52 of the sweep conveyor S is connected to the mechanism 8 exactly in the same way as for the sweep conveyor S in solution E. Below the second joint 11 at the movable pivot point of the peripheral second portion 52 of the sweep conveyor S, the conveyor is divided between its two parts in a seventh joint 53, where the torque of the conveyor or auger is transferred from the central first portion 51 to the peripheral second portion 52 of the conveyor or auger through a universal joint, that allows full power transmission in spite of the angled sweep conveyor S. See
G. A Solution as a Complement to any One of the Solutions A-F, where the Sweep Conveyor S is Divided in a Central First Portion 51 and a Peripheral Second Portion 52, where the Central First Portion 51 of the Sweep Conveyor S is Angled Slightly Upwards
Similar to the solution F, the sweep conveyor S is divided into a central first portion 51 and a peripheral second portion 52, connected by a seventh joint 53, with a fourth angle ζ between them and a universal joint transferring the power between the two parts of the screw. However the fourth angle ζ between the two portions 51 and 52 is here turning the central first portion 51 of the sweep conveyor S slightly upwards, and the fourth angle ζ is either permanent, or fixed and adjustable. The purpose is that the material 74 shall be lifted and thus it shall easier fall by gravity into the central cone 2 in the silo floor 71. This is an advantage when the central cone 2 has a small diameter so that the material 74 does not easily fall into the cone 2 from the point to which the material 74 is moved by the sweep conveyor S. This solution can also be used when there is no central cone in the silo floor 71, but the lower, central end of the diagonal evacuation screw conveyor 1 is just above the silo floor 71. Under the central first portion 51 of the sweep conveyor S, a pile of material 74 will build up when using this solution. When the pile has reached sufficiently high, stored material 74 will eventually start to fall into the diagonal evacuation screw conveyor 1.
H. Device for Suspension of the Sweep Conveyor S Before Filling the Silo 70
The following solution is a useful complement to all the above solutions, solving the problem described earlier with the starting position of the sweep conveyor when the floor 71 of the silo 70 is full with material 74 according to
The problem is solved by two arrangements:
The first one allows lifting of the peripheral end 82 of the sweep conveyor S, by having a vertically rotatable mounting 6 of the sweep conveyor S at its central end 81, as shown in the examples in
The second one is a conveyor holder 60, preferably in the form of a fixed diagonal beam with its lower end fixed to the floor 71 or the holder H, close to the center of the silo 70, and its higher, peripheral, end is close to the silo wall 72. The peripheral end is held by a vertical support 61 preferably standing on the floor 71 close to the wall. The conveyor holder 60 is made so that the sweep conveyor S, when lifted up in its peripheral end 82, can be placed to rest on the conveyor holder, or alternatively that it can be attached to or hooked beside or under the conveyor holder. The vertical angle of the beam and its height at the peripheral end are made so that the sweep conveyor S, when attached to it, is above the surface 75 of the slope of material 74 with resting angle δ in the silo 70 when it is unloaded maximally with the diagonal evacuation screw conveyor 1, as illustrated in
The whole arrangement is shown in
The arrangement is used in the following way:
When the silo 70 is empty, as a preparation before new material 74 is being entered into the silo 70, the sweep conveyor S is placed on, or attached to, the conveyor holder 60. This has to be done in a way that it cannot accidentally fall down, for example by fixing it with a strap or chain, or locking it with a hook, a pin or similar. The conveyor holder can also have a permanent, fixed mechanic locking arrangement, where the locking arrangement can be easily released from a remote point by a handle, for example close to a hatch in the silo wall 72 from where it can be easily reached, or even outside the silo wall 72. In order to reduce the burden to lift the sweep conveyor S up to the conveyor holder 60, a simple winch, hoist, block or similar can be used to elevate the peripheral end 82 of the sweep conveyor S to its locking position.
Any parts sensitive for dust, for example the electric motor drive 4, have to be covered with, for example, a canvas for protection against the stored material.
All cables to the motor drive 4 have to be checked that they are well protected according to the regulations, and that they are well attached to the connection link L and the holder H all the way from the connection on the motor 4 to the point where it exits the silo 70. Otherwise it can be ripped off by the load of the material 74 above it, when the silo is being filled, or by the motion of the operating sweep conveyor S.
Then the silo 70 can be filled with material 74. The sweep conveyor S then becomes completely covered with material 74.
When the silo 70 is being unloaded, the diagonal evacuation screw conveyor 1 is first being used, until no more material 74 is falling by gravity down to the cone 2 at the center of the floor 71 (see the illustration of this situation in
When having reached this point where the diagonal evacuation screw conveyor 1 cannot remove the remaining material 74 by itself, the sweep conveyor S has to be released. Depending on how it has been attached to the conveyor holder 60, this can be done by removing the strap, hook or pin, and by lifting it off from any support it may be placed on, to put it down and let it rest directly on the sloped surface 75 of the stored material 74. If needed, any canvas or similar placed to protect the sweep conveyor motor drive 4 from the stored material 74 is removed. If the motor 4 has no fixed electricity connection, a separate cable is introduced that has to be fixed in a safe way all the way from its entrance point into the silo 70 to the connection on the motor 4, in a way that it cannot be ripped off by the operation of the sweep conveyor S or by any parts of the mechanism 8 installed to secure the right movement of the connection link L. Then any person who has been operating in the silo 70 has to exit the silo 70.
At this point, the diagonal evacuation screw conveyor 1 and the sweep conveyor S can be turned on to operate simultaneously to automatically unload all the remaining material 74 in the silo 70. When the sweep conveyor S has reached a complete tour of 360 degrees, or completed its maximum reach, it is stopped.
The above approach means that the conveyor holder has to be strong enough to resist the pressure and load of both the attached sweep conveyor S, and all the material 74 above, and so that the sweep conveyor S is protected from being deformed by the pressure of the stored material 74 above it.
By this solution, both the very labour intensive operations associated with the prior art are being avoided, alternatively: Either having to enter and mount the sweep conveyor S into the silo 70 every time when it is needed and then having to dismount and remove it every time that the silo 70 will be filled again, or having to uncover the sweep conveyor S covered by the stored material 74, manually by a shovel, every time the unloading of the silo 70 has reached the point where the sweep conveyor S is needed.
It is an advantage to mount a vertical or steep bar 62 below the conveyor holder 60, that can serve to guide or steer the descent of the sweep conveyor S when it is digging into the material 74 below. This is to secure that the sweep conveyor S first digs down vertically until close above the floor 71, and when the sweep conveyor S gets off the lower end of the vertical bar 62, the traction wheel 5 of the peripheral end 82 of the sweep conveyor S reaches the floor and starts to moving the sweep conveyor S forward to advance along the inside of the silo wall 72. Without this guiding, the work of the running sweep conveyor S will result in a movement forward along the inside of the silo wall 72 already before the wheel 5 has reached the floor 71, and thus there will be material 74 left on the floor, unremoved. One way of arranging this guiding effect of the bar 62 is to attach a metal ear on the back side of the sweep conveyor S, that can glide around the bar 62 during the vertical or nearly vertical descent of the sweep conveyor S.
A plurality of embodiments of the present invention are described above, having various components and modes of operation. It is to be noted, however, that features from the various embodiments described herein may freely be combined, unless it is explicitly stated that such a combination would be unsuitable.
Claims
1. A sweep conveyor assembly for use in a silo or granary (70) having a floor (71) and a generally cylindrical wall (72) upstanding from the floor (71) and a discharge apparatus (1) for discharging material (74) from a centre of the floor (71) to an exterior location, the sweep conveyor (S) assembly comprising:
- a sweep conveyor (S) for transporting material (74) inside the silo (70) or granary towards the centre of the floor (71) where it can be discharged by the discharge apparatus (1),
- a holder (H), and
- a link mechanism (8) for connecting the sweep conveyor (S) to the holder (H), said link mechanism (8) comprising a connection link (L) having a first end (83) and a second end (84),
- said first end (83) being configured to be connected to the holder (H) at a fixed pivot point (10) and the sweep conveyor (S) being configured to be connected to the second end (84) of the connection link (L) at a movable pivot point (11), wherein
- the connection link (L) is arranged to rotate about the fixed pivot point (10), forming a first angle (α) between the connection link (L) and an axis extending along a geometrical centre of the holder (H),
- the sweep conveyor (S) is arranged to rotate about the movable pivot point (11), forming a second angle (β) between the sweep conveyor (S) and the connection link (L), whereby the movable pivot point (11) is moved to increase the reach of the sweep conveyor (S), and
- the link mechanism (8) is arranged to control a ratio between the first angle (α) and the second angle (β), and a magnitude of the first angle (α) and second angle (β) is controlled by an angular position of the sweep conveyor (S) such that said first angle (α) and second angle (β) are continuously mutually dependent to always rotate both said conveyor (S) and link (L) in the same direction together about said fixed pivot point (10).
2. A sweep conveyor assembly according to claim 1, wherein the link mechanism (8) controls a position of the connection link (L) and the sweep conveyor (S) during rotation so that the first angle (α) is a function of the second angle (β).
3. A sweep conveyor assembly according to claim 1, wherein the holder (H) is mounted on the floor (71) of the silo or granary (70), or on the discharge apparatus (1).
4. A sweep conveyor assembly according to claim 1, wherein the link mechanism (8) is permanently connected to the holder (H), and/or the sweep conveyor (S) is detachably mounted on the link mechanism (8).
5. A sweep conveyor assembly according to claim 1, wherein the sweep conveyor (S) is mounted to turn at least a complete 360° rotation within the silo (70) about said fixed pivot point (10).
6. A sweep conveyor assembly according to claim 1, wherein the conveyor (S) is mounted to pass underneath the discharge apparatus (1) during rotation.
7. A sweep conveyor assembly according to claim 1, wherein the link mechanism (8) comprises an electrical actuator, and said electrical actuator is arranged to control the relation between the first angle (α) and the second angle (β), and the electrical actuator comprises at least one electric actuator connected between the holder (H) and the first end (83) of the link (L), or connected between the sweep conveyor (S) and the second end (84) of the link (L).
8. A sweep conveyor assembly according to claim 1, wherein the link mechanism (8) comprises a second link (20) that is arranged to control the relation between the first angle (α) and the second angle (β), and the second link (20) has a first end (21) and a second end (22), said first end (21) configured to be connected at a fixed pivot point at a position on the holder (H) different from the fixed pivot point (10) of the connection link (L), said second end (22) configured to be connected to the sweep conveyor (S) at a movable pivot point at another position compared to the pivot point (11) where the connection link (L) is attached to the sweep conveyor (S).
9. A sweep conveyor assembly according to claim 1, wherein the sweep conveyor (S) is connected to the connection link (L) via a vertical connection (A) in such a way that the sweep conveyor (S) passes is beneath the connection link (L) during operation.
10. A sweep conveyor assembly according to claim 1, wherein the first angle (α) is equal to the second angle (β).
11. A sweep conveyor assembly according to claim 1, wherein the connection link (L) comprises a link pivot (12) so that the second end of the connection link (84, 14) can pivot in relation to the first end (83, 13) of the connection link (L), forming a third angle (ε) between said second (84, 14) and first ends (83, 13) of the connection link (L).
12. A sweep conveyor assembly according to claim 1, wherein the sweep conveyor (S) comprises a first (51) and a second (52) conveyor portion that are connected to each other by a sweep conveyor joint (53), the first conveyor portion (51) being configured to be connected to the link mechanism (8).
13. A sweep conveyor assembly according to claim 1, wherein the holder (H) is mounted to be tilted with respect to a vertical axis, such that an end of said conveyor (S) at least partially passes underneath said holder (H) upon rotation.
14. A sweep conveyor assembly according to claim 1, wherein the sweep conveyor (S) is arranged to be pivoted upwards about a turnable joint (6) and attached to a conveyor holder (60) provided on the discharge apparatus (1) or on the holder (H) or standing on supports on the floor (71) or being attached to a silo wall (72), or a combination of any of these.
15. A sweep conveyor assembly according to claim 1, wherein said first end (83) of said connection link (L) is connected to said fixed pivot point (10) by a fixed gear (31).
16. A sweep conveyor assembly according to claim 1, wherein the link mechanism (8) comprises a wire or chain or belt (39) actuator between the first end (83) and the second end (84).
17. A sweep conveyor assembly for use in a silo or granary (70) having a floor (71) and a generally cylindrical wall (72) upstanding from the floor (71) and a discharge apparatus (1) for discharging material (74) from a centre of the floor (71) to an exterior location, the sweep conveyor (S) assembly comprising:
- a sweep conveyor (S) for transporting material (74) inside the silo (70) or granary towards the centre of the floor (71) where it can be discharged by the discharge apparatus (1),
- a holder (H), and
- a link mechanism (8) for connecting the sweep conveyor (S) to the holder (H), said link mechanism (8) comprising a connection link (L) having a first end (83) and a second end (84),
- said first end (83) being configured to be connected to the holder (H) at a fixed pivot point (10) and the sweep conveyor (S) being configured to be connected to the second end (84) of the connection link (L) at a movable pivot point (11), wherein
- the connection link (L) is arranged to rotate about the fixed pivot point (10), forming a first angle (α) between the connection link (L) and an axis extending along a geometrical centre of the holder (H),
- the sweep conveyor (S) is arranged to rotate about the movable pivot point (11), forming a second angle (β) between the sweep conveyor (S) and the connection link (L), whereby the movable pivot point (11) is moved to increase the reach of the sweep conveyor (S),
- the link mechanism (8) is arranged to control a ratio between the first angle (α) and the second angle (β), and a magnitude of the first angle (α) and second angle (β) is controlled by an angular position of the sweep conveyor (S),
- the link mechanism (8) comprises at least two wheels arranged in rolling interaction with each other, and
- the connection link (L) is formed between a center of rotation of each of two wheels, and the wheels are preferably cog wheels.
18. A sweep conveyor assembly for use in a silo or granary (70) having a floor (71) and a generally cylindrical wall (72) upstanding from the floor (71) and a discharge apparatus (1) for discharging material (74) from a centre of the floor (71) to an exterior location, the sweep conveyor (S) assembly comprising:
- a sweep conveyor (S) for transporting material (74) inside the silo (70) or granary towards the centre of the floor (71) where it can be discharged by the discharge apparatus (1),
- a holder (H), and
- a link mechanism (8) for connecting the sweep conveyor (S) to the holder (H), said link mechanism (8) comprising a connection link (L) having a first end (83) and a second end (84),
- said first end (83) being configured to be connected to the holder (H) at a fixed pivot point (10) and the sweep conveyor (S) being configured to be connected to the second end (84) of the connection link (L) at a movable pivot point (11), wherein
- the connection link (L) is arranged to rotate about the fixed pivot point (10), forming a first angle (α) between the connection link (L) and an axis extending along a geometrical centre of the holder (H),
- the sweep conveyor (S) is arranged to rotate about the movable pivot point (11), forming a second angle (β) between the sweep conveyor (S) and the connection link (L), whereby the movable pivot point (11) is moved to increase the reach of the sweep conveyor (S),
- the link mechanism (8) is arranged to control a ratio between the first angle (α) and the second angle (β), and a magnitude of the first angle (α) and second angle (β) is controlled by an angular position of the sweep conveyor (S),
- the link mechanism (8) comprises a hydraulic or pneumatic actuator (41, 42, 45) or a wire or chain or belt (39) actuator between the first end (83) and the second end (84),
- the connection link (L) is formed between the fixed pivot point and the movable pivot point, and
- the hydraulic or pneumatic actuator (41, 42, 45) comprises a first hydraulic or pneumatic actuator (41) connected between the holder (H) and the first end (83) of the link (L), and a second hydraulic or pneumatic actuator (42) connected between the sweep conveyor (S) and the second end (84) of the link (L).
19. A sweep conveyor assembly for use in a silo or granary (70) having a floor (71) and a generally cylindrical wall (72) upstanding from the floor (71) and a discharge apparatus (1) for discharging material (74) from a centre of the floor (71) to an exterior location, the sweep conveyor (S) assembly comprising:
- a sweep conveyor (S) for transporting material (74) inside the silo (70) or granary towards the centre of the floor (71) where it can be discharged by the discharge apparatus (1),
- a holder (H), and
- a link mechanism (8) for connecting the sweep conveyor (S) to the holder (H), said link mechanism (8) comprising a connection link (L) having a first end (83) and a second end (84),
- said first end (83) being configured to be connected to the holder (H) at a fixed pivot point (10) and the sweep conveyor (S) being configured to be connected to the second end (84) of the connection link (L) at a movable pivot point (11), wherein
- the connection link (L) is arranged to rotate about the fixed pivot point (10), forming a first angle (α) between the connection link (L) and an axis extending along a geometrical centre of the holder (H),
- the sweep conveyor (S) is arranged to rotate about the movable pivot point (11), forming a second angle (β) between the sweep conveyor (S) and the connection link (L), whereby the movable pivot point (11) is moved to increase the reach of the sweep conveyor (S),
- the link mechanism (8) is arranged to control a ratio between the first angle (α) and the second angle (β), and a magnitude of the first angle (α) and second angle (β) is controlled by an angular position of the sweep conveyor (S), and
- the sweep conveyor (S) is essentially horizontal when mounted on the link mechanism (8), but one end portion (51) of the sweep conveyor (S) extends upwards at an angle (ζ) from the horizontal direction, said end portion (51) being at the end configured to be connected to the link mechanism (8).
2790563 | April 1957 | McCarthy |
3151749 | October 1964 | Long |
3519152 | July 1970 | Broberg |
4619577 | October 28, 1986 | Swanson |
4669941 | June 2, 1987 | West et al. |
5167542 | December 1, 1992 | Haitmanek |
7967542 | June 28, 2011 | Epp |
8864433 | October 21, 2014 | Hoogestraat et al. |
9809402 | November 7, 2017 | Nelson |
9902575 | February 27, 2018 | Mack |
20040213650 | October 28, 2004 | Epp et al. |
20160096695 | April 7, 2016 | Nelson et al. |
1210920 | September 1986 | CA |
2503906 | October 2006 | CA |
3224491 | January 1984 | DE |
1086913 | March 2001 | EP |
2693710 | January 1994 | FR |
Type: Grant
Filed: Jun 26, 2018
Date of Patent: Mar 2, 2021
Patent Publication Number: 20200223649
Assignee: Forsberg Växtodling AB (Örsundsbro)
Inventor: Gustaf Forsberg (Örsundsbro)
Primary Examiner: James R Bidwell
Application Number: 16/626,967
International Classification: B65G 65/48 (20060101); A01F 25/20 (20060101); B65G 47/16 (20060101);